1. Field of the Invention
The present invention relates to an image generating apparatus, and more particularly, it relates to an image generating apparatus comprising a print head, including a print portion pressing an ink sheet, capable of printing images on papers.
2. Description of the Background Art
An image generating apparatus comprising a print head, including a print portion pressing an ink sheet, capable of printing images on papers is known in general, as disclosed in each of Japanese Patent Laying-Open Nos. 2001-63868 and 7-156487 (1995), Japanese Patent No. 3832097 and Japanese Patent Laying-Open No. 2006-240091, for example.
The aforementioned Japanese Patent Laying-Open No. 2001-63868 discloses a thermal transfer recording apparatus (image generating apparatus) comprising a thermal head (print head), a protective cover provided on a first end of the thermal head for protecting a drive portion driving a heating element provided on the lower portion of the thermal head and guiding transportation of an ink sheet along the lower portion of the thermal head and a sheet guide provided on a second end of the thermal head for guiding transportation of the ink sheet passing through the heating element provided on the lower portion of the thermal head. In the thermal transfer recording apparatus (image generating apparatus) described in Japanese Patent Laying-Open No. 2001-63868, a contact surface of the protective cover coming into contact with the ink sheet in printing is enabled to come into contact with the ink sheet for expanding the central portion of the ink sheet more than both cross-sectional ends thereof, thereby transporting the ink sheet while applying stronger tension to the central portion thereof as compared with both cross-directional ends.
The aforementioned Japanese Patent Laying-Open No. 7-156487 discloses a thermal transfer recording apparatus (image generating apparatus) comprising a thermal head (print head) and a guide bar provided on the rear end of the thermal head for controlling the transport direction for an ink donor film (ink sheet) passing through a heating resistor provided on the lower portion of the thermal head. In the thermal transfer recording apparatus (image generating apparatus) described in Japanese Patent Laying-Open No. 7-156487, a contact surface of the guide bar coming into contact with the ink donor film in printing is bent with downward inclination from the cross-directional central portion toward both ends of the guide bar, so that the guide bar transports the ink donor film while bending both ends thereof in the same direction as the contact surface thereof.
The aforementioned Japanese Patent No. 3832097 discloses a thermal transfer printer (image generating apparatus) comprising a substrate provided with a heating element having a prescribed printing width on the lower surface thereof and a thermal head (print head) including a first guide portion integrally formed on a support plate mounted with the substrate for guiding transportation of a thermal transfer ribbon (ink sheet) and a second guide portion mounted on the lower surface of the substrate for guiding transportation of the thermal transfer ribbon. In the thermal transfer printer (image generating apparatus) described in Japanese Patent No. 3832097, the first guide member is so formed as to vary the sectional shape thereof along the cross direction of the thermal transfer ribbon, to be capable of transporting the thermal transfer ribbon while warping the same in the cross direction. The second guide portion is so formed as to have a sectional shape of a prescribed thickness along the cross direction of the thermal transfer ribbon, to be capable of controlling the position of the thermal transfer ribbon immediately before passage through the heating element.
The aforementioned Japanese Patent Laying-Open No. 2006-240091 discloses a thermal transfer printer (image generating apparatus) comprising a line thermal head (print head), a ribbon guide provided on the line thermal head for guiding transportation of an ink ribbon (ink sheet) along the lower portion of the line thermal head and a separation plate separating the ink ribbon from a recording paper after printing. In the thermal transfer printer (image generating apparatus) described in Japanese Patent Laying-Open No. 2006-240091, a ribbon sliding contact portion of the separation plate uniformly comes into contact with the ink ribbon along the cross direction after printing, so that the ink ribbon adhering to the recording paper in printing can be separated from the recording paper. Further, the ribbon sliding contact portion of the separation plate is provided with a plurality of strip-shaped grooves (ribbon guide portions), to be capable of preventing the ink ribbon from meandering.
However, the aforementioned Japanese Patent Laying-Open No. 2001-63868 proposing the thermal transfer recording apparatus (image generating apparatus) neither discloses nor suggests a member for controlling the transport direction for a recording paper (paper) when the recording paper is fed into the body of the apparatus. If the recording paper (paper) is fed into the body of the apparatus with unnecessary warpage, therefore, the recording paper (paper) may not be properly fed due to interference with any of the internal components of the apparatus. Further, Japanese Patent Laying-Open No. 2001-63868 proposing the thermal transfer recording apparatus neither definitely describes nor suggests the relation between the cross-directional size of the protective cover and the width of the ink sheet. If the cross-directional size of the protective cover is smaller than the width of the ink sheet, therefore, the protective cover comes into contact with only a portion around the cross-directional central portion of the ink sheet, whereby the protective cover can conceivably not reliably apply tension to easily wrinkled cross-directional ends of the ink sheet. Therefore, wrinkling easily caused on the cross-directional ends of the ink sheet cannot be reliably suppressed, in particular.
The aforementioned Japanese Patent Laying-Open No. 7-156487 proposing the thermal transfer recording apparatus (image generating apparatus) neither discloses nor suggests a member controlling the transport direction for a recording paper when the recording paper is fed into the body of the apparatus. If the recording paper is fed into the body of the apparatus with unnecessary warpage, therefore, the recording paper may not be properly fed due to interference with any of the internal components of the apparatus. Further, Japanese Patent Laying-Open No. 7-156487 proposing the thermal transfer recording apparatus neither definitely describes nor suggests the relation between the cross-directional length of the guide bar and the width of the ink donor film. If the cross-directional length of the guide bar is smaller than the width of the ink donor film, therefore, the guide bar comes into contact with only a portion around the cross-directional central portion of the ink donor film, whereby the guide bar can conceivably not reliably apply tension to easily wrinkled cross-directional ends of the ink donor. Therefore, wrinkling easily caused on the cross-directional ends of the ink donor film (ink sheet) cannot be reliably suppressed, in particular.
The aforementioned Japanese Patent No. 3832097 proposing the thermal transfer printer (image generating apparatus) neither discloses nor suggests a member controlling a supply path for a recording medium (paper) when the recording medium is supplied into the body of the printer. If the recording medium (paper) is fed into the body of the printer with unnecessary warpage, therefore, the recording medium (paper) may not be properly fed due to interference with any of the internal components of the printer. In the thermal transfer printer described in Japanese Patent No. 3832097, further, the second guide portion is conceivably so formed as to have a uniformly thick sectional shape along the cross direction of the thermal transfer ribbon, whereby the thermal transfer ribbon is transported while receiving uniform pressing force from the second guide portion on the cross-directional central portion and the cross-directional ends thereof. In this case, no tension is caused between the central and the ends of the thermal transfer ribbon in the cross direction thereof, whereby wrinkling easily caused on the cross-directional ends of the thermal transfer ribbon (ink sheet) cannot be suppressed, in particular.
The aforementioned Japanese Patent Laying-Open No. 2006-240091 proposing the thermal transfer printer (image generating apparatus) neither discloses nor suggests a member controlling the transport direction for the recording paper when the recording paper is fed into the body of the printer. If the recording paper is fed into the body of the printer with unnecessary warpage, therefore, the recording paper may not be properly fed due to interference with any of the internal components of the printer. In the thermal transfer printer described in Japanese Patent Laying-Open No. 2006-240091, further, the outer shape of the ribbon sliding contact portion of the separation plate is conceivably uniformized along the cross direction of the ink ribbon, whereby the ink ribbon is transported while receiving uniform pressing force from the ribbon sliding contact portion of the separation plate on the cross-directional central portion and the cross-directional ends thereof. In this case, no tension is caused between the central portion and the ends of the ink ribbon in the cross direction thereof, whereby wrinkling easily caused on the cross-directional ends of the ink ribbon (ink sheet) cannot be suppressed, in particular.